Portable computing devices, for example Portable Navigation Devices (PNDs) that include GPS (Global Positioning System) signal reception and processing functionality are well known and are widely employed as in-car or other vehicle navigation systems.
In general terms, a modern PND comprises a processor, memory (at least one of volatile and non-volatile, and commonly both), and map data stored within said memory. The processor and memory cooperate to provide an execution environment in which a software operating system may be established, and additionally it is commonplace for one or more additional software programs to be provided to enable the functionality of the PND to be controlled, and to provide various other functions.
Devices of this type will also often include one or more physical connector interfaces by means of which power and optionally data signals can be transmitted to and received from the device, and optionally one or more wireless transmitters/receivers to allow communication over cellular telecommunications and other signal and data networks, for example Bluetooth, Wi-Fi, Wi-Max, GSM, UMTS and the like.
PNDs also usually include a GPS antenna by means of which satellite-broadcast signals, including position data, can be received and subsequently processed to determine a current position of the device.
PNDs are able to determine a route between a first location (for example a start or current location) and a second location (for example a destination). These locations can be input by a user of the device, by any of a wide variety of different methods, for example by postcode, street name and house number. Alternatively, locations may be previously stored locations, such as, shops, restaurants, theatres, travel termini, schools, tourist attractions, viewpoints, sports grounds or swimming baths. Such locations can be referred to as points of interest (POIs), and data concerning such points of interest including their location and other attributes are included in stored map data.
Digital map data is used for a variety of applications, and by a variety of devices, not only PNDs. For example, a wide range of computer applications or internet sites use map data in the display of location maps or in searching or other processes.
The inclusion of data representing the location of points of interest can be useful for a wide range of applications, and can increase the value of the map data. However, in any given area there can be a large number of possible points of interest of different types, and of variable importance, quality or interest.
In known systems for generating and maintaining map data, further attributes of points of interest in addition to their location can be stored. Such attributes for a point of interest can be established by a variety of well known techniques including manually inspecting or evaluating the point of interest, conducting aerial surveys of the point of interest, monitoring the point of interest, making enquiries to staff at the point of interest, obtaining data from a website associated with the point of interest and polling the opinion of visitors to the point of interest. Examples of such attributes may be the popularity of the point of interest or visitor satisfaction, or opening and/or closing times or busy and/or quiet times.
However, establishing the popularity of, or polling visitor opinion for, or determining other attributes of a point of interest using such techniques is often time-consuming and expensive especially as the number of visitors to the point of interest increases. Monitoring such attributes repeatedly over a time period may also compound the time and costs involved, and monitoring such attributes for more than one point of interest can increase the difficulties.